Gas Recirculation Valve (egr Valve) problems of the 1999 Chrysler Cirrus

About 2 years ago, my car began stuttering and stalling out with no warning. The oil light repeated flashes on, the check engine light flashes and then stays on, and the car wont start or just cuts off. The transmission speed sensor was replaced. The transmission was replaced. The oil was changed. This past 3 months alone, it has been at the service department 6 times for this same problem. I am now being told that I need a tune-up, which will cost $700, then the egr needs replaced, and a few other things. However, when the mechanic had it last week, he could not find anything wrong with it. I have found out that the Cirrus vehicles have this same problems that I am having. I was on my way to the mall via the parkway when the car stalled out. Luckily traffic was slow because if I was on the parkway and it stalled out, my sister and I could have gotten killed. There is no predetermined time when these problems occurred. The car only has 89500 miles on it. I have all of my original repair papers. Proper maintenance has always been done on my car. When it works, it is great. Unfortunately, I just never know when it is going to not start.